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| United States Patent |
5,148,822
|
|
Akhtar
|
September 22, 1992
|
Hair straightening method and texturing strengthener compositions
therefor
Abstract
This invention relates to a method of straightening, texturing and
strengthening hair undergoing an alkaline straightening procedure and to
nonacidic aqueous hair texturing and strengthening compositions for use in
conjunction therewith. The texturing and strengthening compositions have a
pH value from at least 8 to about 11 containing at least one
water-dispersible hair texturing and strengthening agent including a
quarternary nitrogen atom with at least one aliphatic alkyl group directly
or indirectly bonded to the quarternary nitrogen atom, the aliphatic alkyl
group having from about 3 to about 22 carbon atoms. Methods for applying
the compositions in post-straightening and pre-straightening procedures
are disclosed.
| Inventors:
|
Akhtar; Muhammad M. (Bolingbrook, IL)
|
| Assignee:
|
Johnson Products Co., Inc. (Chicago, IL)
|
| Appl. No.:
|
781717 |
| Filed:
|
October 22, 1991 |
| Current U.S. Class: |
132/204; 132/205 |
| Intern'l Class: |
A45D 007/04 |
| Field of Search: |
132/204,205
424/70,71
|
References Cited
U.S. Patent Documents
| Re30874 | Mar., 1982 | Dasher et al.
| |
| Re31126 | Jan., 1983 | Dasher et al.
| |
| 3958581 | May., 1976 | Abegg et al.
| |
| 4175572 | Nov., 1979 | Hsiung et al.
| |
| 4237910 | Dec., 1980 | Khalil et al.
| |
| 4304244 | Dec., 1981 | de la Guardia.
| |
| 4361157 | Nov., 1982 | James.
| |
| 4369037 | Jan., 1983 | Matsunaga et al.
| |
| 4416297 | Nov., 1983 | Wolfram et al.
| |
| 4507280 | Mar., 1987 | Pohl et al.
| |
| 4602648 | Jul., 1986 | Syed et al.
| |
| 4663158 | May., 1987 | Wolfram et al.
| |
Other References
Finkelstein, et al., "The Mechanism of Conditioning of Hair with Alkyl
Quarternary Ammonium Compounds," App. Polym. symp. 18, 673 (1971).
Cook "Modern Negro Cosmetics II" DCI 106, 42-44 (May) 1970.
Brooks et al., "Treatment Regimens for `Styled` Black Hair," Cosm. &
Toilet, 98 pp. 59-68 (May) 1983.
Sykes, "The Use of Merquat Polymers," DCI, 126, 62 (1980).
|
Primary Examiner: Millin; V.
Attorney, Agent or Firm: Olson & Hierl, Ltd.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of co-pending application Ser. No.
095,397, filed Sep. 10, 1987, now identified as U.S. Pat. No. 5,060,680.
Claims
What is claimed is:
1. An aqueous hair texturing and strengthening composition for application
to hair about to undergo a highly alkaline hair straightening procedure
comprising an aqueous nonacidic cosmetic vehicle having dispersed therein
about 0.1 to about 8 weight percent on a total composition weight basis of
at least one water-dispersible quaternary nitrogen-containing compound
having at least one alkyl group directly or indirectly bonded to a
quaternary nitrogen group, each said alkyl group containing about 3 to
about 22 carbon atoms, each said compound being selected from the group
consisting of (a) non-proteinaceous, non-polymeric quaternary nitrogen
containing compounds which are in the salt form and which contain said
alkyl group and (b) hydrolyzed proteins which are in the salt form wherein
at least one amino group therein is quaternized to include said alkyl
group, each said compound being characterized by having a positive charge
and being stable when in an aqueous medium at a pH of at least about 6.1 .
2. The composition of claim 1 which additionally includes from zero to
about 5 weight percent on a total composition basis of a dispersed
cationic polymer having a weight average molecular weight of about 3,000
to about 10,000,000.
3. The composition of claim 1 wherein said non-proteinaceous, non-polymeric
quaternary nitrogen containing compound contains an alkyl group that is
derived from a fatty acid.
4. The composition of claim 1 wherein said non-proteinaceous, non-polymeric
quaternary nitrogen containing compound is dicetyldimonium chloride.
5. The composition of claim 1 wherein said hydrolyzed protein is a
hydrolyzed collagen protein in which over 70 percent of the available
amino groups have each been quaternized to incorporate at least one alkyl
group containing about 3 to about 18 carbon atoms each.
6. The composition of claim 5 wherein said quaternized hydrolyzed collagen
protein has a weight average molecular weight of about 2500 to about
12,000 and an isoionic point of about 9.5 to about 11.5, and said alkyl
groups thereof each contain about 12 to about 18 carbon atoms.
7. The composition of claim 1 wherein said hydrolyzed protein is a
hydrolyzed animal protein having at least one alkyl group containing about
12 to about 18 carbon atoms.
8. The composition of claim 1 wherein said hydrolyzed protein is
cocodimonium hydrolyzed animal protein.
9. The composition of claim 1 wherein said hydrolyzed protein is
steartrimonium hydrolyzed animal protein.
10. The composition of claim 1 wherein said salt form has an anion selected
from the group consisting of halides, sulfate, sulfite, phosphate,
nitrate, nitrite, acetate, methylsulfate, ethosulfate and
toluenesulfonate.
11. The composition of claim 1 having a pH of about 6.1.
12. A method for straightening hair comprising the steps of:
(a) first applying to the hair a composition of claim 1;
(b) then applying to the resulting hair a highly alkaline hair straightener
for a time sufficient to at least partially straighten said hair;
(c) rinsing substantially all of said straightener from said so
straightened hair; and
(d) washing said so rinsed hair with a neutralizing shampoo having a
neutral to acidic pH.
13. The method of claim 12 wherein the applied composition in step (a) has
a pH of at least about 6.1.
14. The method of claim 12 wherein the applied composition in step (a)
additionally contains about 0.1 to about 3.5 weight percent of a
water-dispersible cationic polymer having a weight average molecular
weight of about 3,000 to about 10,000,000.
15. The method of claim 12 wherein after said rinsing and before said
washing, said so rinsed hair is contacted with an aqueous hair
conditioning composition.
16. The method of claim 15 wherein said aqueous hair conditioning
composition is an aqueous hair texturing and strengthening composition of
claim 1.
17. The method of claim 16 wherein said aqueous hair texturing and
strengthening composition has a pH of at least about 8.
18. The method of claim 16 wherein the composition applied in step (a) has
a pH of about 6.1.
Description
TECHNICAL FIELD
This invention relates to the art of chemically straightening human hair
and to texturing strengthener compositions for use in conjunction with
alkaline hair straighteners. More particularly, non-acidic compositions
are provided which contain a cationic texturing strengthening agent to
simultaneously texturize and strengthen hair undergoing a highly alkaline
straightening procedure.
BACKGROUND OF THE INVENTION
Until now, practitioners of chemical hair straightening arts have been
unable to successfully increase and maintain negatively-charged cation
receptive sites in alkali-straightened (relaxed) hair to simultaneously
strengthen and restore its textural quality to that substantially
resembling hair in relatively good condition.
Most commonly used relaxers are based on hydroxide-containing alkalis,
sulfites or thioglycolates. Of these, the most effective and popular are
alkaline straightener compositions that produce stable lanthionine
linkages in the hair. These chemical hair straighteners usually contain
relatively strong alkalis, such as sodium hydroxide, potassium hydroxide,
calcium hydroxide, lithium hydroxide and guanidine hydroxide. The highly
alkaline conditions (pH 12 to 14) of these products, however, causes a
substantial amount of swelling in human hair. Consequently, some
hydrolysis of the polypeptide chains in the hair protein at about pH 12.5
is inevitable.
Prolonged or unnecessary exposure of hair to a strong alkali weakens,
breaks and even dissolves the hair. Thus, it is an accepted practice to
minimize the time that the hair is exposed to highly alkaline hair
straighteners. Towards this end, substantially all the straightener is
immediately rinsed from the hair as soon as the desired partial or
complete straightening effect is achieved. Further, to remove any residual
hair straightener remaining in the rinsed hair, and to deswell the hair,
an acidic neutralizer is applied immediately thereafter to the rinsed
alkali-treated hair. Generally this acidic neutralizer is a nonalkaline
shampoo or an acid rinse having a pH below 7, usually in a pH range
between about 1 to about 6 and preferably close to the isoelectric region
of human hair, approximately pH 4.
Some success in preventing further alkali attack on the hair is achieved by
deswelling the hair in the foregoing manner. However, the textural quality
of acid-treated hair is harsh and strawlike, unless known conditioners are
included in the shampoo or rinse. The term "conditioners" refers to
cosmetically useful emollients, such as oils, quaternary ammonium salts,
cationic polymers and the like, known to those skilled in hair
conditioning art.
It is known that human hair is negatively charged, i.e., more anionic,
above its isoelectric region, and hence, more receptive to adsorbing
cationic materials. There is also some indication that the cationic
qualities of certain quaternary ammonium salts are enhanced under alkaline
conditions. Finkelstein, et al., "The Mechanism of Conditioning of Hair
with Alkyl Quaternary Ammonium Compounds," App. Polym. Symp., 18, 673
(1971), for example, report that the cationic properties of
stearyltrimethyl ammonium chloride are greater at pH 7.5 than at pH 4.5.
However, any attempt to enhance or sustain the cation-receptivity of
alkali-straightened hair by further exposing it immediately to a
non-acidic composition having a pH greater than 7 is generally avoided.
Thus, the non-polymeric quaternary ammonium salts often used for hair
conditioning are employed at relatively low pH values rather than at
higher pH values. Under alkaline conditions, such compounds tend to
deposit an unacceptable delustering coating on the hair. Also, because of
their relatively small molecular size, they are easily removed from the
hair so conditioning benefits obtained are temporary.
As a result, cationic polymers, especially those containing quaternary
nitrogen atoms, are more often used in hair conditioning compositions,
because these polymers are usually substantive to hair at acidic pH
values. The term "substantive" cannot be defined by distinctive
physicochemical properties, but involves mechanisms such as adsorption,
ion exchange and chemical interaction. As used herein, the term
"substantive" or its grammatical variant "substantivity" refers to the
retention of a cationic material deposited or adsorbed on the hair through
several shampoo applications.
Not all cationic polymers, however, are alkali-compatible or stable under
alkaline conditions. Some cationic polymers must first be complexed with
some anionically active component already present on the hair or in the
neutralizing shampoo to form a conditioning reaction product.
Proteinaceous materials that are water-soluble and substantive to hair are
also known desirable compounds. A number of water-soluble hydrolyzed
protein compounds are commercially available, some of which display
cationic qualities under acidic conditions. However, their utility under
alkaline conditions is limited, because they become neutral or anionic in
character and some degradation of the amide groups in the protein portion
takes place. Consequently, their use in non-acidic compositions is
generally avoided.
Prior attempts have been limited, therefore, to applying conditioners under
acidic or neutral conditions to at least improve the tactile feel, if not
the strength of the alkali-straightened hair.
In one approach, a non-alkaline composition containing one or more of the
foregoing conditioners is applied to the hair before the hair
straightener. However, one drawback of this approach is that any
conditioning benefit achieved generally does not survive the subsequent
highly alkaline chemical straightening procedure. In addition, these
conditioners may weaken the strength of the hair straightener product or
interfere with its effectiveness.
This drawback was partially overcome by including a quaternary
nitrogen-containing cationic polymer in the alkaline hair straightener
product as described in U.S. Pat. No. 4,175,572. Such a product is
presently marketed. However, the residual alkalinity in the hair following
use of this product is substantially immediately neutralized by
application of a non-alkaline neutralizing shampoo.
In another approach, a conditioning nonalkaline shampoo neutralizer is
employed immediately after rinsing the straightener from the hair with
water. However, a shampoo, by the manner in which it must be used,
contacts the hair too briefly to maximize adsorption of cationic
materials. Further, alkali-weakened hair may not withstand the
manipulative actions inherently required for the shampooing process so
some hair loss or breakage can occur.
U.S. Pat. No. 4,602,648 (hereafter the '648 patent) discloses the use of
hydrolyzed proteins and/or cationic polymers in a "pre-shampoo normalizer"
so-called because it is applied between the straightening step and the
shampooing step. Several products following such a procedure are presently
being marketed. However, the effectiveness of such normalizer compositions
suffers the same drawbacks of prior acidic compositions.
The pre-shampoo normalizers of the '648 patent are acidic or nonalkaline
compositions that are adjusted by the addition of acid to a pH of between
2.5 and 7. Thus, these compositions decrease, rather than increase,
cation-receptive negatively-charged sites in the hair as the acidity of
the composition neutralizes the alkaline residue in the hair. Thus, this
approach constitutes, in effect, an acidic neutralization procedure,
because the '648 patent normalizer step is followed by a shampooing step
to remove both residual straightener and residual normalizer composition
from the hair.
The '648 patent purports to take advantage of the sensitive state of the
hair at a relatively high alkaline pH of between about 9 and 11 after the
straightener treatment to mediate damage and improve the aesthetic
qualities of the straightened hair. However, we have found from experience
that when the method of this patent is followed, substantive conditioning
and strengthening are not simultaneously achieved. This was determined by
measuring the strength and subjective textural qualities of the
straightened hair.
There is a need for a relatively simple method and a product that
simultaneously strengthen and enhance the cation-receptivity of hair
undergoing or about to undergo a highly alkaline hair straightening
procedure. We have now surprisingly found that the cation-receptivity of
alkali-straightened hair can be enhanced and sustained, while the hair is
simultaneously strengthened, by applying the non-acidic compositions of
this invention to hair in a post-straightening and pre-straightening step.
The hair straightening method and texturing strengthener compositions of
this invention satisfy that need.
SUMMARY OF THE INVENTION
This invention relates to a method of simultaneously straightening,
texturing and strengthening hair undergoing an alkaline straightening
procedure, and particularly to non-acidic aqueous texturing and
strengthening compositions for use in conjunction with such highly
alkaline hair straighteners.
The term "highly alkaline" used in connection with hair straighteners
refers to products that contain alkaline straightening agents that provide
a pH value of about 12 to about 14. These are generally known to those
skilled in the hair straightening art as "lye" and "no-lye" relaxers. The
term "non-acidic", as applied to compositions of this invention, relates
to vehicles containing no ionizable hydrogen-containing substances capable
of neutralizing residual alkali on the hair from the hair straightener
product.
In one embodiment of the method of this invention, a texturing and
strengthening agent contained in an aqueous composition having a pH of
from between at least 8 to about 11 is applied in a post-straightening
step, as disclosed herein, to enhance and sustain cation receptive
negatively-charged sites in hair which has just undergone an alkali
straightening procedure. The post-straightening step follows substantially
immediately after the hair straightener is rinsed from the hair.
In another embodiment, the above method includes applying an auxiliary
amount of the texturing and strengthening agent contained in an aqueous
texturing and strengthening composition in a pre-straightening step to
hair about to undergo the straightening procedure. An auxiliary amount
refers to an amount of hair texturing and strengthening agent applied to
either the virgin outgrowth portion or previously treated outgrowth
portion of the hair in addition to the amount of hair texturing and
strengthening agent applied in the post-straightening step. The
pre-straightening step is substantially immediately before the hair
straightener is applied to the hair. The auxiliary amount of hair
texturing and strengthening agent applied to the hair in the
pre-straightening step can be provided in a non-acidic aqueous composition
that is the same or different from that applied in the post-straightening
step.
Texturing and strengthening is substantially achieved within about 5
minutes of the post-straightening step. However, the method includes a
shampooing step to cleanse the hair and scalp of residual hair
straightener, if any, and excess texturing and straightening composition.
The term "texturing" or its grammatical variant "texturize" refers to those
physical, chemical and mechanical characteristics of hair associated with
subjectively discernible changes in the textural qualities of the hair and
its tensile strength.
The terms "strength" and "strengthening" as used in connection with
alkali-straightened hair refer to changes in mechanical properties of hair
fibers related to the overall dynamic and static moduli of a hair fiber,
as measured by stress-strain and breaking force techniques. Loss of
strength and swelling are generally associated in straightened hair with
weakened fiber integrity, such that the alkali-straightened hair can break
during shampooing or combing. Weakened hair is also associated with poor
textural qualities (spongy, rubbery) that negatively affect its hand.
The term "hand", as used herein, refers to the subjective feel of the hair
or tactile reaction to such textural qualities as smoothness, softness and
flexibility when the hair is combed or manipulated during styling. The
term "fiber integrity" as used herein includes those physical and chemical
characteristics of intact hair subjectively associated with the mechanical
properties of hair condition, i.e., easy combability, manageability and
hand.
We have surprisingly found that hair undergoing a highly alkaline
straightening procedure can be simultaneously textured and strengthened by
aqueous texturing and strengthening compositions of this invention which
have a pH of at least 8 or greater and contain certain cationic hair
texturing and strengthening agents.
In one embodiment, an aqueous hair texturing and strengthening composition
of this invention has a pH value from at least 8 to about 11, preferably
from at least 8 to about 9. The composition includes at least one
water-dispersible hair texturing and strengthening agent including a
quaternary nitrogen atom with at least one aliphatic alkyl group directly
or indirectly bonded to the quaternary nitrogen atom. The aliphatic alkyl
group has from about 3 to about 22 carbon atoms. For achieving the desired
pH, the compositions can include a base.
Suitable water-dispersible texturing and strengthening agents include
quaternary ammonium derivatives of a hydrolyzed animal protein and
quaternary nitrogen-containing compounds including at least one aliphatic
alkyl group bonded directly or indirectly to the quaternary nitrogen atom.
Each alkyl group preferably contains from about 8 to about 18 carbon atoms
and the remainder of the groups bonded to the quaternary nitrogen atom
include alkyl groups having from 1 to about 4 carbon atoms, a benzyl
radical and combinations thereof. The term "water-dispersible", as used
herein in connection with cationic materials, includes water-soluble
compounds that form substantially clear solutions when dispersed or
dissolved in water.
In a preferred embodiment of the composition, the hair texturing and
strengthening agent is a quaternary ammonium derivative of a hydrolyzed
collagen protein in which over about 70 percent of the available amino
groups have been quaternized to incorporate at least one aliphatic alkyl
group having from about 3 to about 18 carbon atoms in the aliphatic alkyl
group. A particularly preferred quaternary ammonium derivative of
hydrolyzed collagen protein incorporates from about 12 to about 18 carbon
atoms in at least one aliphatic alkyl group, has a weight average
molecular weight from about 2500 to about 12,000, and has an isoionic
point from about 9.5 to about 11.5.
For augmenting the texturing effect on alkali-straightened hair, a hair
texturing and strengthening composition of this invention includes a
water-dispersible cationic polymer. The term "cationic polymer" as used
herein includes quaternized polymers containing at least one positively
charged nitrogen atom in each repeating unit of the polymer chain,
unquaternized polymers having tertiary amino nitrogen groups that become
quaternized when protonated and corresponding copolymers thereof. A
particularly preferred polymer is a polydiallyldialkyl ammonium chloride
homopolymer in which the alkyl group contains from 2 to 3 carbon atoms,
and the polymer has a weight average molecular weight of about 100,000.
The methods and compositions of this invention have many advantages and
benefits. One advantage is that the cation receptivity of alkali-treated
hair is enhanced and sustained to strengthen the hair while shampoo
resistant texturing benefits are provided. Another benefit is that
compositions can be applied to previously untreated virgin growth portions
of the hair to make the hair more cation-receptive prior to undergoing the
alkaline straightening procedure. Yet another benefit is that previously
straightened outgrowth portions of the hair can also be textured with
non-acidic compositions without interfering with the subsequent alkaline
straightening procedure.
Still further benefits and advantages of the present invention will become
apparent to those skilled in the art from the detailed description of the
invention, the examples and the claims that follow.
DETAILED DESCRIPTION OF THE INVENTION
The method of this invention provides for texturing and strengthening hair
about to undergo or having just undergone an alkaline hair straightening
(relaxing) procedure. Such compositions typically contain as the active
hair straightening agent relatively strong alkalis such as sodium
hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide,
guanidine hydroxide and quaternary ammonium hydroxide. For convenience,
hair that has undergone a highly alkaline hair straightening procedure at
a pH of about 12 to about 14 is referred to herein simply as
alkali-straightened hair or relaxed hair.
The mechanism of simultaneously texturing and strengthening
alkali-straightened hair by compositions of this invention is not fully
understood. We believe that negatively charged sites in
alkali-straightened hair are sustained by compositions of this invention
having a pH of at least 8 resulting in enhanced cation substantivity on
the hair without impairing fiber integrity. The available positively
charged sites in the texturing and strengthening agent may bind to the
negatively charged sites in the hair to provide a discernible improvement
in the textural qualities of the alkali-straightened hair that lasts
through subsequent shampoo procedures. Further, the strength of the
alkali-treated hair simultaneously improves as measured by break force and
intermittent stress strain modulus techniques described below. However,
the effectiveness of the present methods and compositions does not depend
upon and is not limited by the foregoing description of a proposed
mechanism.
The texturing and strengthening agent of this invention is a
water-dispersible quaternary nitrogen-containing compound having at least
one aliphatic alkyl group directly or indirectly bonded to a quaternary
nitrogen atom. The aliphatic alkyl group preferably includes from about 3
to about 22 carbon atoms. Particularly preferred aliphatic alkyl groups
are lipophilic fatty acid derivatives of a natural or synthetic fatty acid
or a source of fatty acids, either linear or branched, containing from
about 12 to about 18 carbon atoms.
Suitable texturing and strengthening agents are proteinaceous and
nonproteinaceous quaternary ammonium compounds. These compounds include
quaternary ammonium derivatives of a hydrolyzed animal protein and
quaternary nitrogen-containing compounds including at least one aliphatic
alkyl groups bonded directly or indirectly to the quaternary nitrogen
atom. Each alkyl group preferably contains from about 8 to about 18 carbon
atoms and the remainder of the quaternary nitrogen bonds include alkyl
groups having from 1 to about 4 carbon atoms, a benzyl radical and
combinations thereof.
Preferably, the quaternary nitrogen of the quaternary ammonium compound
retains its positive charge and is stable at an alkaline pH in the range
of at least pH 8 to about 11. Especially preferred are quaternary ammonium
compounds that are substantive to hair and which disperse in water to
provide solutions that are substantially clear at a pH above 8.
Examples of water-dispersible proteinaceous quaternary ammonium compounds
include derivatives of chemically-modified hydrolyzed animal protein, such
as quaternary ammonium derivatives of hydrolyzed collagen protein
including at least one aliphatic alkyl group having from about 12 to about
18 carbon atoms in the aliphatic alkyl group. Compounds of this type that
are commercially available include the following compositions aid by
Croda, Inc., New York, N.Y.: lauryldimethylammonium hydrolyzed animal
protein (trade name CROQUAT L); coconutdimethylammonium hydrolyzed animal
protein (trade name CROQUAT M); stearyldimethylammonium hydrolyzed animal
protein (trade name CROQUAT S); stearyltrimethylammonium animal protein
(trade name CROTEIN Q); and the following compositions sold by Inolex
Chemical Company, Philadelphia, Pa.: cocoamidodimethylhydroxypropylamino
hydrolyzed animal protein (trade name LEXEIN QX3000) and
oleamidopropyldimethylamine hydrolyzed animal protein (trade name LEXEIN
CP125). Another illustrative quaternary ammonium derivative of collagen
protein that includes an aliphatic alkyl group containing 3 carbon atoms
is commercially available from Hormel, Oak Brook, Ill., under the name
PROLAGEN MP-1. The foregoing list is intended to be illustrative and not
limiting.
Particularly preferred is the quaternary ammonium derivative of hydrolyzed
collagen protein sold under the trade name CROQUAT M by Croda, Inc. This
compound, and the structurally related CROQUAT L and CROQUAT S
derivatives, are reported to have at least 70 percent of the available
amino acid groups in the collagen quaternized. Thus, these compounds are
alkyl dimethyl ammonium chloride derivatives having a plurality of
quaternary nitrogen-containing alkyl dimethyl moieties covalently bonded
directly to the peptide chain and are reported to have a hydroxyproline
content of about 4.5 percent to about 6 percent. The Croquat materials
reportedly have an isoionic point in the range of about 10 to about 11.5
and retain their net positive charge at a pH value of about 9.5.
Likewise, another preferred quaternary ammonium derivative of hydrolyzed
collagen protein is sold under the trade name CROTEIN Q by Croda, Inc.
This material is reported to have over 90 percent of its available amino
acid groups quaternized and the amino acid residues are indirectly bonded
to a quaternary nitrogen atom by an 18 carbon aliphatic alkyl chain. The
aliphatic alkyl chain including the hydrolyzed protein is directly bonded
to a quaternary nitrogen atom with the remaining quaternary nitrogen bonds
taken up with methyl groups. CROTEIN Q is reported to have a isoionic
point in the range of about 9.5 to about 10.5 and is positively charged at
all pH values up to an isoelectric point of about 10.
The term "isoionic point" refers to the pH range in which the proteinaceous
quaternary ammonium compound is ionically charged. The term "isoelectric
point" refers to the pH at which the proteinaceous quaternary ammonium
compound has no net charge.
Non-proteinaceous water-dispersible quaternary nitrogen-containing
compounds containing at least one aliphatic alkyl group bonded directly or
indirectly to the quaternary nitrogen atom include quaternary ammonium
compounds in the form of a salt having a substantially innocuous inorganic
or organic anion such as a halide, preferably chloride or bromide,
sulfate, sulfite, phosphate, nitrate, nitrite, acetate, methylsulfate,
ethosulfate and toluenesulfonate.
Illustrative examples of non-proteinaceous water-dispersible quanternary
nitrogen-containing compounds include octyltrimethyl ammonium chloride;
decyltrimethyl ammonium chloride; lauryldimethylethyl ammonium chloride;
lauryltrimethyl ammonium chloride; cetyldimethylethyl ammonium chloride;
cetyltrimethyl ammonium chloride; tetradecyltrimethyl ammonium chloride;
stearyltrimethyl ammonium chloride; 3-behenoyloxy-2-hydroxypropyltrimethyl
ammonium chloride; behenyltrimethyl ammonium chloride; behenyltrimethyl
ammonium methosulfate. Also suitable are dialkyldimethyl ammonium
chlorides wherein each of the alkyl groups is a saturated group having
from about 8 to about 18 carbon atoms, such as distearyldimethyl ammonium
chloride; dilauryldimethyl ammonium chloride, didecyldimethyl ammonium
chloride; di-(hydrogenated tallow)-dimethyl ammonium chloride. Mixed
higher alkyl trimethyl ammonium chlorides containing mixtures of
predominantly long-chain aliphatic alkyl radicals having from about 8 to
about 18 carbon chains in the alkyl group may also be used such as
derivatives of coconut oil, tallow, soya bean oil, cottonseed oil, babassu
oil, palm oil, etc. Compounds that correspond to the foregoing may also be
employed where the anion is other than a halide, as noted above.
A particularly preferred non-proteinacious water-dispersible quaternary
nitrogen-containing compound has the CTFA adopted name of dicetyldimonium
chloride and is an N-hexadecyl-N,N-dimethyl-1-hexadecaminium chloride
corresponding to the commercial material sold under the trade name ADOGEN
432CG by Sherex Chemical Company, Inc., Dublin, Ohio.
Additional illustrative quaternary ammonium compounds include "benzyl
quats" such as aliphatic alkyldimethylbenzyl ammonium chlorides having
from about 8 to about 18 carbon atoms in the aliphatic alkyl group. These
compounds include cetyldimethylbenzyl ammonium chloride;
stearyldimethylbenzyl ammonium chloride; tetradecyldimethylbenzyl ammonium
chloride; cetyldimethylbenzyl ammonium chloride;
n-dodecyldimethyl-p-chlorobenzyl ammonium chloride; laurylpyridinium
chloride; cetylpyridinium chloride; alkyl isoquinolinium chlorides or
bromides having about 8 to about 18 carbon atoms in the alkyl chain, such
as laurylisoquinolinium chloride; N-(acylcolaminoformylmethyl)-pyridinium
chlorides and bromides wherein the acyl radical contains from 8 to 18
carbon atoms, such as octoyl, lauroyl, palmitoyl and stearoyl, and the
like. Another exemplary material is N-soya-N-ethyl morpholinium
ethosulfate, such as the material sold under the trade name ATLAS G271 by
ICI Americas, Inc., Wilmington, Del. This listing is by way of
illustration and is not intended to be limiting.
For practicing the method of this invention, the compositions contain at
least one or more texturing and strengthening agents. Preferred
compositions contain at least one quaternary ammonium derivative of a
hydrolyzed protein as the texturing and strengthening agent.
For practicing the principles of this invention, an effective amount of a
texturing and strengthening agent is dispersed in water with sufficient
base, if needed, to adjust the pH of the composition to between at least
pH 8 to about pH 11, preferably from at least pH 8 to about pH 9, more
preferably from about pH 8.1 to about pH 8.5.
An effective amount of total texturing and strengthening agents present is
from about 0.1 percent to about 8 percent by weight, preferably from about
0.2 percent to about 6.0 percent by weight, and more preferably from about
0.5 percent to about 5.0 percent by weight. Percent by weight as used
herein refers to the weight of active dry solids based on the total weight
of the composition. It is recognized that actual suitable amounts are
limited only by the solubility or dispersibility of a selected compound in
water and by economic considerations. It is also recognized that amounts
greater than 8 percent can be used, but such amounts are believed
unnecessary and wasteful.
Bases suitable for adjusting the pH of the compositions include alkali
metal hydroxides, and lower alkyl organic bases in which the alkyl group
contains from 1 to about 6 carbon atoms commonly employed in the cosmetic
arts. While it is recognized that a volatile base, such as ammonia, as
well as the foregoing nonvolatile bases, can be used for purposes of
achieving the desired pH, ammonia is not preferred to avoid swelling the
alkali-treated hair or irritating the skin.
Exemplary alkali metal hydroxides include sodium hydroxide and potassium
hydroxide. The amount of sodium hydroxide employed is relatively small for
adjusting the pH and, thus, is well below the amounts normally used in
hair straighteners.
Exemplary lower alkyl organic bases include primary alkylamines such as
ethylamine or propylamine; secondary alkylamines such as diethylamine,
morpholine or ethylpropylamine; tertiary amines such as triethylamine or
quinuclidine; and preferably a hydroxyalkylamine containing 2 to 6 carbons
per alkyl group bonded to the amine nitrogen atom such as
monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine,
diisopropanolamine, triisopropanolamine, 2-amino-1-butanol,
1-amino-2-methyl-2-propanol and 2-amino-2-methyl-1-propanol. A
particularly preferred base is triethanolamine.
For purposes of augmenting the texturing effect on alkali-straightened
hair, a water-dispersible cationic polymer can be included in compositions
of this invention. Suitable cationic polymers preferably include
quaternized polymers containing at least one positively charged nitrogen
atom in each repeating unit of the polymer chain, but can include
unquaternized polymers that behave like cationic polymers when protonated
and corresponding copolymers of the foregoing. Preferably, cationic
polymers useful in compositions of this invention retain their cationic
positive charge at a pH above at least 8, provide substantially clear
solutions when dispersed in water and are substantive to hair.
Broadly, cationic polymers are useful in concentrations of about 0.01
percent to about 5 percent by weight, preferably in amounts of about 0.1
percent to about 3.5 percent by weight, and more preferably in amounts of
about 0.2 to about 2.5 percent by weight. The percentage is expressed as
the weight of dry solids based on the total weight of the composition. The
weight average molecular weights of the polymers useful herein are broadly
between about 3000 and about 10,000,000, with various useful polymers
having a generally more narrow average molecular weight range.
A number of cationic polymers, their manufacturers and general description
of their composition can be found in the CTFA Cosmetic Ingredient
Dictionary, 3rd ed., 1982 and in the CTFA Cosmetic Ingredient Dictionary,
3rd ed., Supplement, 1985, both published by the Cosmetic Toiletry and
Fragrance Association, Inc. (CTFA) and incorporated herein by reference.
The official CTFA name assigned to ingredients appearing therein or as
assigned by the manufacturer, when known, will be employed for
convenience.
Preferred cationic polymers include those prepared from
polydiallyldialkylammonium salts containing from 2 to 3 carbon atoms in
the alkyl group. The preparation of these polymers is described in U.S.
Pat. Nos. 3,288,770 and 3,412,019. These polymers are sold commercially
under the trade name MERQUAT by Merck & Company, Inc., Rahway, N.J.
Particularly preferred is a polydiallyldimethylammonium chloride
homopolymer designated polyquaternium-6 by the CTFA and sold under the
trade name MERQUAT-100. This polymer is described as having a weight
average molecular weight of approximately 100,000 and is supplied as a 40
percent aqueous solution. Also preferred is a copolymer of
diallyldimethylammonium chloride with acrylamide designated
polyquaternium-7 by the CTFA and sold under the trade name MERQUAT-550.
This material is described as having a weight average molecular weight of
approximately 500,000 and is supplied as an 8 percent aqueous solution. A
discussion of these materials and their properties is found in Sykes et
al., "The Use of Merquat Polymers," Drug Cosm. Ind. , 126, 62 (1980) which
is incorporated herein by reference.
Other useful cationic polymers are quaternary ammonium derivatives of
natural guar gum assigned CTFA names of guar hydroxypropyltrimonium
chloride. Natural water-soluble polymers of cationic guar that are
compatible over a wide pH range of from about 3 to about 11 are
commercially available, sold under the trade names JAGUAR C-13, C-14-8,
C-15 and C-17 by Celanese Corporation, Louisville, Ky. Guar is a
galactomannan with a structure composed of a straight backbone chain of
D-mannopyranose units with a side branching unit of D-galactopyranose on
every other unit and having an average molecular weight in the range of
about 200,000 to about 300,000. A description of these cationic gums is
found in Freeland et al., "Cationic Guar Gum," Cosmet. Toilet., 99, 83
(1984) which is incorporated herein by reference.
A listing of useful cationic polymers which is not intended to be
exhaustive or limiting follows:
adipic acid/epoxypropyl diethylenetriamine copolymer (sold by Hercules
Inc., Wilmington, Del., under the name DELSETTE 101);
adipic acid/dimethylaminohydroxypropyldiethylenetriamine copolymers (sold
by Sandoz Chemicals Corporation, Charlotte, N.C., under the name
CARTARETIN);
polyquaternium-2, a poly[N-(3-dimethylamino)
propyl]-N'-[3-(ethyleneoxyethylene dimethylamino)propyl]urea dichloride
(sold by Miranol Chemical Company, Inc., Dayton, N.J. under the name
Mirapol A 15);
quaternary ammonium polymers formed by the reaction of dimethyl sulfate and
a copolymer of vinyl pyrrolidone and N,N-dimethylaminoethylmethacrylate
(sold by GAF Corporation, Wayne, N.J. under the names GAFQUAT-734 and
GAFQUAT-755); polymers of hydroxyethyl cellulose reacted with
epichlorohydrin and quaternized with trimethylamine (sold by Union Carbide
Corporation, Danbury, Conn. under the trademark POLYMER JR and available
in a range of various molecular weight sizes);
copolymers prepared from acrylamide and N,N-dimethylaminoethyl methacrylate
and quaternized with dimethyl sulfate (sold by Hercules, Inc. under the
name RETEN);
aminoethylacrylate phosphate/acrylate copolymer (sold by National Starch &
Chemical Corporation, Bridgewater, N.J., under the name CATREX);
polyquaternium-1 a polymeric quaternized dimethylbutenyl ammonium chloride
terminated with quaternized triethanolamine groups (sold by Onyx Chemical
Company, Jersey City, N.J., under the name ONAMER M);
poly(methacrylamidopropyltrimethyl ammonium chloride) obtained by the
polymerization of the corresponding monomer sold by Texaco Chemical
Company, Bellaire, Tex. under the name MAPTAC; and
quaternized poly(ethyleneimine), quaternized poly(vinylamine), quaternized
poly-4-vinyl pyridine and the like prepared by methods generally known in
the art.
Thus, a useful texturing and strengthening composition of this invention
can include from zero to about 5 percent by weight of cationic polymer.
Amounts greater than 5 percent can be employed but are considered
unnecessary and wasteful. Additionally, the compositions can contain any
of a variety of cosmetically known adjuvants, including emulsifiers,
preservatives, viscosity modifying thickeners, auxiliary solvents such as
alcohols or glycols, proteins, perfume and the like.
It is recognized that some emulsifiers and some quaternary ammonium
compounds may have some surface active characteristics useful for
distributing the composition through the hair during application. However,
surface active agents typically associated with foaming shampoo products
are not necessary for practicing the texturing and strengthening aspects
of this invention. Texturing is independent of any interaction between the
texturing and strengthening agent and any surface active component and
does not depend on any co-reaction therebetween. Thus, texturing and
strengthening compositions are preferably substantially free of
foam-producing surface active agents.
In the method of this invention, highly alkaline hair straightener products
are applied to the hair by methods well known in the art to at least
partially straighten those portions of the hair that have received no
prior chemical hair straightening treatment, i.e., substantially virgin
outgrowth. It is generally well known that the length of time that the
hair is exposed to a highly alkaline straightener or relaxer product
varies with the amount of curl in the hair and the strength of the
alkaline straightening agent. Typically, this length of time is determined
by the practitioner based on the amount of partial or complete removal of
natural curl desired. Less than about 20 minutes, preferably less than
about 15-18 minutes, is desirable.
For purposes of texturing and strengthening the alkali-treated hair,
substantially all the hair straightener product is removed from the hair,
preferably by rinsing with water. Substantially immediately thereafter, a
post-straightening amount of texturing and strengthening composition is
applied. For this purpose, the composition has a pH of from between at
least 8 to about 11, and preferably from between at least pH 8 and about
pH 9 as described above. The composition is applied in an amount
sufficient to contact the hair fibers when it is stroked through the hair
in a gentle downward motion from the scalp to the end portions. A
sufficient amount was found to be about 1 ounce per average head of hair.
Surprisingly, we have found that such a post-straightening application of a
non-acidic composition of this invention having a pH value of at least 8
or higher had no adverse effect on the physical integrity of such recently
alkali-treated hair. This finding is contrary to what would normally be
expected and is contrary to what is presently practiced. Also, surprising,
we found that hair contacted in this manner for a relatively short time of
about 5 minutes was simultaneously textured and strengthened and had
decreased residual alkalinity.
Residual alkalinity in the alkali-treated hair was measured by sampling the
hair immediately after rinsing the straightener with water, extracting the
residue on the hair by soaking the hair sample in water and then measuring
the pH of the extraction medium as described in Example 3. For comparison,
the same procedure was followed after the post-straightening texturing
procedure. Surprisingly, the measurable residual alkalinity of the
alkali-treated hair was lowered by texturization.
Auxiliary amounts of the texturing and strengthening agent can be applied
to the virgin outgrowth before applying the hair straightener. For this
purpose the texturing and strengthening agent can be provided by the same
composition having a pH of at least 8 applied in a post-straightening
procedure. Alternatively, a different non-acidic composition can be used.
Likewise, the texturing and strengthening agent used in the
post-straightening step can be the same as or different than that used in
the pre-straightening step.
Auxiliary amounts of texturing and strengthening agent can be applied to
previously straightened outgrowth portions of the hair contained in a
non-acidic composition to augment texturing benefits.
Strengthening achieved by the method of this invention is substantially
complete following the post-straightening application step. Unlike
conventional procedures, therefore, the method of this invention does not
depend on the use of a neutralizing shampoo for strengthening the
alkali-treated hair. However, the texturizing/strengthening step can be
followed, if desired, by a shampoo, with or without an intervening water
rinse.
Employing a shampoo is usually preferred for purpose of cleansing and
removing from the hair residual hair straightener, if any, and any excess
amount of post-straightening composition from the hair or scalp. Any of a
number of conventional shampoos typically used by practitioners in the
hair straightening arts can be employed. Typically, such shampoos are
neutralizing shampoos having an acidic to neutral pH. For purposes of
practicing the principles of this invention, the type of shampoo employed
need not be so limited as long as the shampoo components do not interact
with or inactivate the texturing component in the hair or decrease the
strength of the hair. The texturing benefits achieved by the method of
this invention survived through multiple shampoo applications and were
thus long-lasting effects.
Texturing and strengthening of the hair is reflected by a discernibly
improved tactile feel, such as smoothness, silkiness and normally
associated attributes of conditioning that influence combing,
manageability, etc., as well as perceived attributes such as luster. It is
generally recognized that hair condition is a complex concept that depends
on a variety of physical quantities that are subjectively evaluated by
practitioners. Thus, some instrumental techniques were also employed to
measure functional relationships of various physical quantities of
strengthening associated with subjective hair texturization properties.
One of the instrumental techniques employed measures the stress-strain
modulus of hair in terms of fiber elongation and axial swelling while it
is actually undergoing a chemical straightening procedure. This technique
is called the intermittent modulus technique because changes in the
strength of the hair under an intermittently applied additional load are
measured. For this purpose, a laboratory model of an intermittent modulus
device was constructed and employed.
The intermittent modulus device comprises a balance attached to a beam
which controls illumination of a photocell and generates a current. Light
control for the photocell is electronically regulated and current is
measured on a strip chart recorder.
The instrument balance beam is attached to a test hair fiber. The hair
fiber is anchored at each end by a vinyl tab and is laterally positioned.
The lateral position of the fiber is controlled by a micrometer, and
controls are provided on the instrument to assure exact fiber alignment.
The length of the hair fiber for convenience is preferably of a gauge
length of about 1.5 centimeters but is not so limited. A constant load is
placed on the hair fiber and an additional load is applied at intermittent
intervals. For example, a constant load of 0.5 grams can be applied, and
additional loads of 0.5 grams can be applied at 30 second intervals.
Changes in the length of the fiber cause proportional changes in the
position of the recorder pen. Fiber axial swelling is influenced and
controlled by applied chemical treatments thus making it possible to
assess the treatment in terms of fiber axial swelling. Axial swelling
changes are magnified 200 times on the recorder chart, so that a 30
millimeter pen excursion is equivalent to 1 percent change in fiber length
for a fiber of 1.5 centimeters gauge length.
Using this technique, therefore, fiber integrity is measured in terms of
both fiber strength and fiber elongation. Fiber strength is determined by
the height of the vertical pen excursion. For example, the greater the
chemical attack, the weaker the fiber will become and this will be
reflected by a greater vertical excursion by the pen. Fiber elongation is
related to supercontraction and is reflected by changes in the vertical
position of the pen on the recorder chart. Thus shortening of the fiber as
it weakens is readily observable. Restoration of fiber integrity is judged
as a reversal of weakened fiber strength and supercontraction, i.e., less
supercontracted.
From our experience, calculated values of percent loss in tensile strength
of hair that has been straightened with highly alkaline "lye" or "no-lye"
relaxers obtained with the intermittent modulus technique compare
favorably with those obtained by commercially available tensile testers,
such as the Scott Tensile Tester, GCA/Precision Scientific, Chicago. Ill.
Also in this regard, a description of the construction of a laboratory
model of an analogous device used to study the performance of depilatories
can be found in Elliot, "Use of a Laboratory Model to Evaluate the factors
Influencing the Performance of Depilatories," J. Soc. Cosm. Chem., 25, 367
(1974).
This invention is further illustrated in the following Examples, which are
not intended to be limited.
EXAMPLE 1
This example illustrates texturing and strengthening compositions suitable
for use on hair that is about to undergo or has just undergone a highly
alkaline hair straightening procedure. For convenience, the following
formulae (A-G) contain a preferred texturing and strengthening agent,
cocodimonium hydrolyzed animal protein (ingredient no. 1), and where
present, a preferred cationic polymer, polyquaternium 6 (ingredient no.
2).
The compositions below are prepared by dispersing ingredients nos. 1-5 in
water (ingredient 7) at a temperature of about 35 to about 45 degrees C.
together with relatively slow mechanical agitation until homogeneous,
cooling relatively quickly to a temperature of about 30 to about 25
degrees C. and adding ingredient no. 6 to a pH from at least 8 to about
8.5, preferably between about pH 8.1 and about 8.4.
______________________________________
Active Weight Percent
(dry solids basis)
Ingredient A B C D E F G
______________________________________
1. Cocodimonium hydrolyzed
2.4 2.4 1.2 2.5 5.0 3.5 0.2
animal protein (Note a)
2. Polyquaternium 6 (Note b)
1.2 1.2 -- -- 5.0 0.1 --
3. Polysorbate-20 (Note c)
1.0 -- -- 0.5 -- -- --
4. DL-Panthenol -- 1.0 -- -- -- -- --
5. Preservative Q.S.
6. Triethanolamine (85% in
Q.S.
water) to pH 8-8.5
7. Water, deionized, to
Q.S.
100 percent
______________________________________
Note a: CTFA adopted name for a coconut dimethyl ammonium derivative of
hydrolyzed collagen protein sold under the trade name CROQUAT M by Croda,
Inc., supplied as a 40 percent solution in water, and staed to have an
approximate molecular weight of 2,500.
Note b: CTFA adopted name for poly(dimethyldiallyl ammonium chloride)
corresponding to the material sold under the trade name MERQUAT100 by
Merck Chemical Division, Merck & Company, Inc., supplied as a 40 percent
solution in water, and stated by the manufacturer to have a weight averag
molecular weight of approximately 100,000.
Note c: CTFA adopted name for polyoxyethylene (20) sorbitan monolaurate,
nonionic emulsifier.
EXAMPLE 2
This example illustrates nonacidic compositions suitable for use in
applying auxiliary amounts of texturing and strengthening agent to hair
that is about to undergo a highly alkaline hair straightening procedure.
For convenience, the same preferred texturing and strengthening agent and
preferred cationic polymer used in Example 1 are employed.
______________________________________
Active Weight Percent
(dry solids basis)
Ingredient H I J K L M N
______________________________________
1. Cocodimonium hydro-
0.2 0.8 1.2 0.25 1.0 3.5 1.5
lyzed animal protein
(Note a, Example 1)
2. Steartrimonium hydro-
0.45 0.45 0.45 0.5 0.5 -- --
lyzed animal protein
(Note d)
3. Dicetyldimonium
1.5 0.75 0.75 1.5 -- 0.2 --
chloride (Note e)
4. Polyquaternium 6
0.2 0.4 0.02 0.25 -- 0.1 1.0
(Note b, Example 1)
5. Cetearyl Alcohol
2.0 2.0 2.0 2.0 1.5 0.5 --
(and) Ceteareth-20
(Note f)
6. Emulsifying Wax-NF
2.0 2.0 2.0 2.0 -- 1.0 --
(Note g)
7. Propylene glycol
25.0 25.0 25.0 25.0 -- -- --
8. Preservative Q.S.
9. Water, deionized,
Q.S.
to 100 percent
______________________________________
Note d: CTFA adopted name for a stearyltrimethyl ammonium derivative of
hydrolyzed collagen sold under the trade name CROTEIN Q by Croda, Inc.,
supplied as a 90 percent active powder, and stated to have an approximate
molecular weight of 12,000.
Note e: CTFA adopted name for Nhexadecyl-N,N-dimethyl-1-hexadecaminium
chloride corresponding to the material sold under the trade name ADOGEN
432 CG by Sherex Chemical Co., Inc. supplied as a 75 percent solution in
water.
Note f: CTFA adopted name corresponding to a nonionic emulsifier sold
under the name Promulgen D by Amerchol Corporation.
Note g: CTFA adopted name corresponding to a nonionic emulsifier that is
mixture of higher fatty alcohols and ethylene oxide sold under the trade
name Polawax Regular by Croda, Inc.
The compositions are prepared by dispersing all ingredients, except nos. 2
and 3 in water at a temperature of about 80 degrees C. with gentle
mechanical agitation until homogeneous, cooling the solution relatively
quickly to about 50 degrees C. and adding ingradients nos. 2 and 3.
Mechanical agitation is maintained until the composition has cooled to
about 25 degree C.
EXAMPLE 3
This example illustrates the post-straightening benefit of texturing and
strengthening hair that has just undergone a highly alkaline hair
straightening procedure by applying a nonacidic composition of this
invention without increasing the residual alkalinity of the alkali-treated
hair.
For this study, a commercial "no-base" type hair straightener product of
regular strength containing about 2 to about 2.5 percent sodium hydroxide
(C) was employed. Eleven female volunteers, each having varying degrees of
natural curl in their hair had their hair straightened in the following
procedure.
Because each of the volunteers had a history of previous chemical
straightening of their hair, the nonvirgin outgrowth portion was treated
with a pre-straightening auxiliary amount of texturing and strengthening
composition. The hair was parted into four sections from the forehead to
the nape and then across the head from ear to ear. Approximately 5
milliliters of the non-acidic composition H of example 2 was applied to
each sectioned outgrowth portion and distributed by combing to contact the
fibers from the start of the outgrowth portion to the tip ends. A total of
about 1/4 ounce to about 1/2 ounce of composition was applied to the
entire head of hair depending on each subject's needs.
The straightener product was applied to the virgin curly new growth
portions of the hair in the conventional manner following the
manufacturer's instructions. For subjects having hair characterized as
fine, medium and coarse, the respective total contact time with the highly
alkaline chemical hair straightener was about 13 minutes, about 15 minutes
and about 18 minutes, respectively.
When the desired amount of straightening was obtained, the hair was rinsed
with water thoroughly until substantially all visible traces of the
straightener product were removed from the hair and scalp. Excess water
was squeezed from the hair and immediately afterwards, several relatively
small tresses totaling at least about 250 milligrams (mg) of hair were
sampled by cutting them from randomly selected scalp areas. The cut
tresses were pooled, identified as "after relaxer" samples and allowed to
air dry at ambient room temperature and humidity.
The hair having just undergone alkali-straightening as well as the
outgrowth portion was then treated with a post-straightening amount of
texturing and strengthening agent using composition A of Example 1. This
composition was clear and had a pH of 8.3. Approximately one ounce of
texturing composition was applied to the hair and was gently combed
through from the crown to the nape to contact all portions of the hair
fibers. After about 5 minutes, several relatively small tresses of hair
were again randomly sampled as described earlier. The pooled samples were
identified as "after texturing" and were allowed to air dry at ambient
room temperature and humidity. Except for the removal of hair samples as
described above, each of the volunteers had their hair subsequently
shampooed with a commercial non-alkaline neutralizing shampoo (E) and
styles as practiced in conventional procedures. The neutralizing shampoo
contained an amphoteric surfecant and had a pH of about 5.5 to about 6.5.
The residual alkalinity of the sampled hair identified above was measured
by soaking the hair in deaerated distilled water and measuring the pH of
the extraction medium using the following procedure. The deaerated
distilled water was prepared by boiling distilled water (Hinckley &
Schmidt) and then cooling it to ambient room temperature just before using
it. For measuring pH, a Radiometer model TTA60 titration assembly was used
in conjunction with a Radiometer model PHM64 research pH meter.
After the hair sampled had dried, it was prepared for pH measurements by
cutting an individually indentified tress into a relatively fine size and
thoroughly mixing the cutting to obtain a substantially uniformly
distributed sample. An amount of about 300 to about 500 mg of this finely
cut hair was accurately weighed into a titration vessel adapted for use
with the Radiometer titration assembly, covered lightly and set aside
until needed. This procedure was followed for all tresses obtained,
retaining each identified sample in separate vessels. For comparison
purposes, the amount of finely cut hair weighed for measuring the residual
alkalinity after the relaxer step and after the texturing step was about
the same, where possible.
A volumetric amount of 10 milliliters of the distilled water, prepared as
described above, was pipetted into an empty dry titration vessel, mounted
on the titration assembly and stirred for 10 minutes. The pH of the water
was measured at the end of the 10 minutes and recorded. This procedure was
repeated several times during the course of this study to determine the
average pH of the water using separate vessels for each measurement. Based
on these measurements, the average pH value of the water was about 6.18.
To measure the residual alkalinity of the hair sampled and identified as
"after relaxer", 10 milliliters of the deaerated distilled water described
above were volumetrically pipetted into the titration vessel containing
the accurately weighed finely cut hair sample. This vessel was then
mounted on the titration assembly and the hair/water mixture was stirred
for 10 minutes, after which the pH of the extraction medium was measured
and recorded. The procedure was repeated with a second sample and the
average pH value of the duplicate samples was determined. The individual
pH values between duplicates agreed within 0.1 pH unit. This same
procedure was followed for hair sampled and indentified as "after
texturing."
The average pH values of the extraction medium obtained from the amount of
hair sampled taken from each of the eleven volunteers (1-11) are compared
in the following Table.
______________________________________
Average pH of Medium
(A) (B)
Mg After Mg After (A-B)
Volunteer
Hair Relaxer Hair Texturing
Change
______________________________________
1 500 7.62 500 7.16 -0.46
2 500 8.13 500 7.71 -0.42
3 337 9.26 339 8.60 -0.66
4 500 9.12 500 7.70 -1.42
5 372 8.92 320 7.59 -1.33
6 500 9.14 500 7.33 -1.81
7 500 9.26 271 7.37 -1.89
8 358 9.14 316 8.24 -0.90
9 309 9.44 401 7.76 -1.68
10 500 9.30 500 8.40 -0.90
11 423 7.84 353 7.55 -0.29
Average 8.83 7.76 -1.07
______________________________________
The overall variation between the pH values obtained for any two separate
volunteers can be attributed to differences expected for variable rinsing
times used by the beautician as required for that individual volunteer.
The results show that the residual alkalinity on the alkali-straightened
hair was decreased by the texturing and strengthening composition. As
seen, in all cases the residual alkalinity of the medium for textured hair
samples (column B) was lower than that of the medium for relaxed hair
sample (column A), by from 0.29 to 1.89 pH units with a average decrease
of about one pH unit. Thus, at the end of the texturing and strengthening
procedure, the alkalinity of the residue on the textured hair was
substantially neutral (average value of pH 7.76) whereas after the
relaxer, it was alkaline (average value pH 8.83).
EXAMPLE 4
This example illustrates the texturing benefit of the method of this
invention using a nonacidic texturing and strengthening composition of
this invention (A) compared to that of an acidic commercial "normalizer"
product (B) embodying the principles of U.S. Pat. No. 4,602,648.
The general procedure of Example 3 was followed, except that no hair
tresses were sampled. For comparison purposes, the same procedure of
Example 3 was practiced on one side of the head (identified as side A)
employing composition H of Example 2 as the auxiliary texturing and
strengthening agent before applying the commercial regular strength
straightener product (C), and composition B of Example 1 having a pH of
8.15 as the post-straightening texturing and strengthening composition.
The amounts applied to the hair were adjusted accordingly as needed.
On the opposite side of the head (identified as side B) the hair was
straightened, following the manufacturer's instruction using the regular
strength hair straightener product component (D) supplied with the acidic
pre-shampoo normalizer product (B). The amounts applied were adjusted for
half-head usage. Following instructions, the pre-shampoo normalizer
product (B) was applied to the hair after rinsing the hair straightener
product (D) from the hair with water, massaged through the hair gently.
After a period of about 5 minutes the hair was shampooed. The same
neutralizing shampoo (E) was employed on both sides of the head. Multiple
shampoo application of at least two to three were employed, as needed.
Experienced beauticians evaluated and compared the characteristics of the
products and the texture and strength of the hair as shown below in a
study using 50 female volunteer subjects.
______________________________________
Number of Notations
Characteristic Side A Side B No Diff.
______________________________________
Softer feel on wet hair after
43 -- 7
post-straightener treatment
Easier wet combing after
44 1 5
shampooing
Hair loss (more breakage)
-- 3 47
Easier dry combing
1 -- 44
Preferred dry feel of hair
6 -- 40
More straightening
7 5 38
Sheen -- -- 50
Manageability -- -- 50
Static flyaway -- -- 50
Overall preferred
36 4 10
Alkali sensation on scalp
6 13 --
______________________________________
The results show that applying a texturing and strengthening agent of this
invention contained in a nonacidic composition to hair about to undergo
and to hair having just undergone a highly alkaline hair straightening
procedure provided more discernible conditioning benefits than did a
commercial product employing an acidic pre-shampoo normalizer composition.
These benefits show that the texturing effect survived multiple shampoo
applications.
EXAMPLE 5
This example illustrates the benefit of strengthening hair undergoing a
highly alkaline hair straightening procedure with nonacidic texturing and
strengthening compositions of this invention. Strengthening was determined
by intermittent modulus technique using the intermittent modulus device
described above.
For this study, fibers of natural brown-colored intact hair (R. Weintraub,
New York, N.Y.) of gauge length 1.5 centimeters were individually mounted
between vinyl tabs. A constant load of 0.5 grams was used with an
additional intermittent load of 0.5 grams applied at 30 second intervals.
Restoration of fiber integrity was determined by observing changes in the
strength and elongation (supercontraction) of the fiber undergoing the
hair straightening procedure. These changes were recorded on a Heath strip
chart recorder having a 10 millivolt sensitivity using a chart speed of
0.1 inches per minute. A 30 millimeter pen excursion for this length fiber
was equivalent to a 1 percent change in fiber length. For example, the
strength of the fiber weakened and supercontracted during a relaxer
treatment as reflected by changes in the vertical position of the pen on
the chart. Thus, strenthening was determined by observing reversals in
this pattern, based on proportional changes in the recorder pen position.
A series of studies were made to observe the strengthening effects of
applying nonacidic compositions of this invention to the hair at various
stages of the hair straightening procedure. In all studies, the relaxer
product used was the commercial regular strength sodium hydroxide
containing relaxer creme (C) of Example 3, applied as supplied in an
amount sufficient to coat the fiber, left on the hair to the point where
maximum supercontraction was recorded (usually about 3 to about 5
minutes), after which the relaxer was rinsed from the fiber with tap
water.
The variations in the process were either in stage (I) where the hair about
to undergo straightening was pretexturized by applying the nonacidic
composition H (pH 6.1) of Example 2 immediately before the relaxer, or in
stage (II) where the hair having just undergone straightening was
texturized by coating the fiber with nonacidic composition A (pH 8.32) of
Example 1 for about 5 minutes, or in stage (III) where the
post-straightening texturization procedure in stage (II) was followed by a
tap water rinse (WR) or in stage (IV) where the entire procedure was
terminated by shampooing with the commercial nonalkaline neutralizing
shampoo (S) of Example 3, except that the shampoo was diluted 1:9 parts
with tap water for convenience.
These variations are summarized in the following Table in study nos. 1-6.
For comparison, study nos. 7-9 were included to observe the strengthening
effects achieved by practicing the principles taught in the '648 patent by
substituting the commercial acidic normalizer product (N) used in Example
4 in stage (II). For further comparison, a counterpart to the acidic
normalizer containing the texturing and strengthening agent of this
invention (composition T, pH 3.5) was prepared for use in stage (II) shown
in study no. 10.
Composition T was prepared following the procedure of Example 1 for
composition B, except that triethanolamine was omitted and instead
included 0.5 weight percent boric acid and 0.2 weight percent citric acid
along with 0.2 weight percent of a polyquaternium 10 having an average
molecular weight of about 100,000. (Polyquaternium 10 is the CTFA adopted
name for a polymeric quaternary ammonium salt of hydroxyethyl cellulose
reacted with a trimethyl ammonium substituted epoxide corresponding in
this instance to Polymer JR 30M sold by Union Carbide Company.) Each study
shown in the Table was done in duplicate. The stage performed is shown by
the alphabetical designation of the composition used while the omission of
the stage is indicated by a dash.
______________________________________
Study no. Stage I Stage II Stage III
Stage IV
______________________________________
1 -- -- -- S
2 -- A WR --
3 H -- -- --
4 H A WR --
5 H -- -- S
6 H A -- S
7 -- N -- S
8 H N WR S
9 H N WR --
10 -- T WR --
______________________________________
The results showed that water rinsing alkali-straightened hair, in itself,
strengthens the alkali weakened fiber to a certain extent, and that an
acidic neutralizing shampoo, as in study no. 1 contributes further to
producing a less supercontracted, i.e., less rubbery, more springy, fiber.
This result and study generally agrees with what is conventionally
practiced and known.
More importantly, the study also confirmed that the texturing and
strengthening agent of this invention applied to the hair in stage II
strengthened the hair and that strengthening was substantially completed
at the end of stage II. The strengthening achieved was substantially
equivalent to that provided upon use of an acidic neutralizing shampoo.
Thus, the neutralizing shampoo step in Stage IV provided no further
increased strength benefit, based on study nos. 2, 4, and 6. Additionally,
the strengthening effect obtained was unaffected by rinsing with water
after the texturing procedure.
Any measurable benefit of the texturing and strenthening agent on fiber
properties applied in stage I was generally obscured by the overwhelming
weakening effect of the relaxer in study nos. 3, 4, 5 and 6. This result
showed that the nonacidic composition H did not interfere with the
straightening action of the relaxer even though the measurable pH of
composition H was inherently mildly acidic (pH 6.1). While this study was
unable to detect strengthening benefits from applying this particular
nonacidic composition, we know from experience and the texturing results
in Example 4 show that composition H contributes to augmenting the
texturing effect on the hair.
The texturing and strengthening agent of this invention generally showed a
pattern of strengthening seen on the recorder as a gradual increase in
fiber length that leveled off when complete. Thus, while the mechanism is
not fully understood, the result suggests that the cation receptive
negative sites in the hair are sustained while the nonacidic composition
of this invention simultaneously strengthens and texturizes the hair in
stage II. A similar gradual pattern was seen in study no. 10 where the
composition was purposely acidified. The result confirms that
strengthening is substantially as effective as an acidic neutralizer.
This observation was further confirmed when the commercial normalizer
product N was used instead in stage II in study nos. 7-9. The pH of this
product was measured as pH 4.6. Unlike the nonacidic texturing and
straightening compositions of this invention, product N reversed
supercontraction of the relaxed hair relatively rapidly but strengthening
overall was not superior to that obtained with the strengthening agent in
composition A of the invention. This result suggests that the acid
components in product N deswell the fiber rapidly owing to acid
neutralization of the alkaline residue on the hair as one would expect.
However, any benefit achieved from such rapid reversal in terms of lasting
conditioning was not observed as shown in Example 4.
In another study, the procedure of study no. 5 was repeated except the
commercial regular strength relaxer used contained a cationic polymer
along with sodium hydroxide (CP). Strengthening effects observed were
similar to those of Study no. 5.
EXAMPLE 6
This example illustrates nonacidic compositions having a pH of at least 8
to about 8.5 suitable for use in applying texturing and strengthening
agent in an auxiliary amount in a pre-straightening step or in a
post-straightening step or in both steps to hair undergoing an alkaline
hair straightening procedure.
______________________________________
Active Weight Percent
(dry solids basis)
Ingredient O P Q R S T
______________________________________
1. Cocodimonium hydro-
-- 2.4 2.4 2.4 2.0 --
lyzed animal protein
(Note a, Example 1)
2. Steartrimonium hydro-
2.4 0.9 0.9 0.9 1.0 --
lyzed animal protein
(Note d, Example 2)
3. Dicetyldimonium
-- 1.5 1.5 1.5 1.5 1.5
chloride
(Note e, Example 2)
4. Polyquaternium 6
1.2 1.2 1.2 1.2 1.0 1.5
(Note b, Example 1)
5. N-soya-N-ethyl mor-
-- 0.5 -- -- -- 0.5
pholinium ethosulfate
(Note h)
6. Hydrolyzed animal
-- 2.2 2.2 -- -- --
protein (Note i)
7. Cetearyl Alcohol
-- 2.0 2.0 2.0 2.0 2.0
(and) Ceteareth-20
(Note e, Example 2)
8. Emulsifying Wax-NF
-- 2.0 2.0 2.0 2.0 2.0
(Note f, Example 2)
9. Stearic Acid -- 1.5 -- -- 1.0 1.5
10. Propylene glycol
-- 15.0 -- -- 10.0 15.0
11. Preservative Q.S.
12. Thickener Q.S. -- Q.S. Q.S. Q.S. Q.S.
13. Triethanolamine (85%
Q.S.
in water) to pH 8-8.5
14. Water, deionized
Q.S.
to 100 percent
______________________________________
Note h: Such as ATLAS G271 sold by ICI Americas, Inc. as a 35 percent
aqueous solution.
Note i: CTFA adopted name for a hydrolyzed animal protein sold under the
trade name LEXEIN X250 by Inolex Chemical Company, supplied as a 55
percent aqueous solution.
EXAMPLE 7
This example illustrates the benefit of strengthening hair undergoing a
highly alkaline hair straightening procedure with non-acidic texturing and
strengthening compositions of this invention applied in a texturing
procedure practiced in a pre-straightening step and in a
post-straightening step. Strengthening was determined by tensile wet break
strength technique as described below.
For this study (No. 1) a 5-inch tress of natural dark brown hair (DeMeo
Brothers, New York, N.Y.) 2 grams in weight was used. To this tress, 5
grams of the commercial regular strength hair straightener C used in
Example 3 was applied. After 18 minutes, the hair straightener was removed
by thoroughly rinsing the hair tress using warm tap water (Stage 1). The
texturing and straightening composition A of Example 1 was applied in an
amount of 1 gram to the rinsed straightened hair. After 5 minutes, the
composition was rinsed from the hair using warm tap water (Stage 2).
The tensile wet elongation and break strength of the textured tress was
determined by removing 25 fibers from the tress after Stage 1 and again
after Stage 2. The fibers were equilibrated in water overnight. The gram
force required to break the wet fiber under elongation while submerged in
water was measured using the Scott Tensile Tester, and mean break force
determined. For comparison, fibers from an untreated tress were similarly
tested as a control.
In another study (No. 2), the procedure of study No. 1 was repeated,
excepted that 0.5 grams of auxiliary texturing and straightening
composition B of Example 2, was also applied to the tress immediately
before applying the hair straightener.
For comparison a regular straightening procedure was practiced in a third
study (No. 3) in which 5 grams of the commercial regular strength hair
straightener containing cationic polymer CP used in Example 3 was applied
to a similar tress and the procedure of Study No. 1 up to Stage 1
otherwise followed. After rinsing the hair straightener from the hair, the
straightened hair was shampooed using two sudsings with the non-alkaline
neutralizing shampoo E of Example 3, rinsing thoroughly (Stage 3). The
results in the following table show the percent decrease in strength after
straightening (Stage 1), and either after post-straightening tensile
texturing (Stage 2) or after neutralizing (Stage 3) and the percent regain
in original pre-straightened strength.
______________________________________
A B
Mean Percent Percent
Tensile Gram Decrease Regain in
Study No. Break Force in Strength
Strength
______________________________________
1 (Stage 1)
43.48 -17.79 --
1 (Stage 2)
50.48 -4.55 75
2 (Stage 1)
47.87 -9.46 --
2 (Stage 2)
53.00 +0.21 100
3 (Stage 1)
44.09 -16.64 --
3 (Stage 3)
48.82 -7.70 50
Untreated 52.9 -- 0
(Control)
______________________________________
The data were found statistically significant at a confidence level of 95
percent when subjected to a Standard Statistical T-Test Analysis.
The break strength results of Study No. 1 showed that the texturing
compositions of this invention restored tensile strength to the
alkali-straightened hair to a level approaching the original
pre-straightened level when applied in a post-straightening procedure. In
study No. 2, the original tensile strength of the hair was substantially
regained when auxiliary texturing composition was applied in a
pre-straightening step as well. This finding showed that the texturing
procedure provided a lasting protective effect.
By applying auxiliary texturing composition before straightening, the
decrease in tensile strength caused by the alkaline hair straightener was
lessened by about 8.33 percent comparing stages 1 of Studies No. 1 and No.
2.
The results further show that the texturing and strengthening compositions
in the method of this invention restored tensile strength to a greater
extent than was restored by a non-alkaline neutralizing shampoo in Study
No. 3.
The present invention has been described with respect to preferred
embodiments. It will be clear to those skilled in the art that
modifications and/or variations of the disclosed compositions and methods
can be made without departing from the scope of the invention set forth
herein.
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